Looks like a critter keeper, which many users use here. I can't tell but do you have a heater, thermometer, and light source? Those are essential. Also, how many gallons is it? I would also recommend getting a cave or something for your betta to hide in because he may become stressed otherwise.

I would take out about 3/4 of that gravel out. The more room your betta has to swim the happier he or she will be. Other than that, bettas like places to hide, so a small cave (mug or decoration) would be great to add as well.

Other than a light and some sort of cave (if you do use some sort of cup, make sure it has never been in the dishwasher... I personally prefer terracotta pots. I got one for each of my betta tanks for about 1 dollar at the local greenhouse... just make sure the hole in the bottom isn't sharp or big enough for them to get through. When in doubt, cover it up somehow.) I think you're covered.